Casting ingots



Nov. 22, 1932. L; N. MCDONALD CASTING INGOT Filed June 5. 1930 jawenfor:

Patented Nov. 22, 1932 UNITED STATES LOUIS N. MCDONALD, 0F YOUNGSTOWN,OHIO CASTING INGOTS Application filed June 5, 1930. Serial No. 459,270.

This invention relates to a method of casting ingots and has for one ofits objects the revision of a novel method of casting wherey the heat ofthe molten metal is retained in the upper end of the ingot and scams andholes in the upper end of the ingot known as piping are prevented. VHeretofore specially formed refractory hot tops have generally been usedto retain the heat of the molten metal in the upper ends of ingots, andsuch articles while maintaining the heat in the top of the ingot aresubject to many disadvantages.

The refractory hot tops are very fragile which leads to much breakage inshipment and handling. When refractory hot tops come in contact with themetal during the pouring operation they are apt to crumble, slag, crackor spall, and this results in particles of the hot top being included inthe ingot. It is also the general practice to break the refractory hottops off of the ingot so that they are used but once, making their costquite a problem.

The present invention provides a novel method whereby all of the aboveobjections are overcome and the expense of using hot tops is materiallyreduced.

In the drawing:

Figure 1 is a side elevation, partly in section, of the upper end of aningot mold having the apparatus for carrying out this method appliedthereto.

Figure 2 is a top plan view thereof.

Figure 3 is a view similar to Figure 1 but taken at right anglesthereto.

Figure 4 is a sectional view showing the form-removed and the filling ofgranulated refractory in place.

The apparatus for carrying out the novel I method of this inventionconsists of the ordinary ingot mold 2 in the upper end of which an openended metal form member 3 is suspended.

The member 3 is of materially less transverse dimensions than theinterior dimensions of the ingot mold 2 so as to leave a space 4surrounding the member when it is centered in the mold. The member 3 isprovided with upwardly extending side wall extensions 5 whichhave earsor lugs 6 extending outwardly therefrom and adapted to engage the topedge of the ingot mold 2 to support the member 3 in position within themold. The side wall extensions 5 are provided with aper 1 tures oropenings 7 to receive a crane hook or other lifting element ,to withdrawthe member 2 after the ingot is cast.

The inside face or wall of the member 3 I is tapered upwardly andinwardly from its lower to its upper end to facilitate the withdrawal ofthe member from the upper endor neck of the ingot after the metal hassolidified within the form 3.

The outside face or wall-of the member 3 is tapered outwardly andupwardly from its lower end for a very short distance, as at 9, and thenis tapered upwardly and inwardly similar to the inside face or wall.

In carrying out the method of this lnven 7 tion the member 3 will bepositioned as shown in the upper end of the ingot mold 2 and the moltenmetalwill be poured into sald mold until it reaches the lower end of theform 3 or to a level slightly above the lower end of, the form 3 butbelow the upper end of the tapered portion 9. -At this point the pouringof the molten metal will be interrupted for a sufficient length of timefor the molten metal to chill or harden around so the lower end of theform 3 to prevent any additional flow ,of metal upwardly between theoutside face of the form 3 and the inside face of the mold 2.

After the molten metal has chilled or hardened around the lower'end ofthe form 3 the pouring of the molten metal will be continued until theform 3 is filled to the desired point. \Vhen the form 3 has been filledthe metal will be permitted to chill, harden or set until a shell isformed around the interior of the form 3 of sufiicient thickness tosupportthe molten interior of thesink-head or upper end of the ingot.After this shell hasformed, the form 3 will be removed and the space hetween the sink-head or neck A of the ingot B and the .inside of the mold2 will be filled vitha quantity of granulated refractory 10 whichwillserve to retain the heat in the up- 1 0 per end or neck of the ingot. 0

- top of the sink-head when found necessary Refractory material alsowill be put on top tween the portion of said ingot cast in saic of theneck or sink-head A in the manner form and the sides of the lngot moldWlth shown in Figure 4, to further insulate the granulatedrefractorymaterial to prevent the top of the ingot. Obviously, however, thererapid coohng of the upper portlon of the fractory material may beomitted from on ingot.

or desirable. my hand.

Ordinarily the ingots will be poured short in the way shown in Figure 4.It frequently is found necessary or desirable to increase' the weight ofthe ingot B to prevent waste when blooms or slabs of definite Weight areto be cut from the rolled ingot.

The increased weight is obtained by adjusting the member 3 verticallywithin the mold 2 to vary the distance it projects downwardly within themold.

A convenient way of doing this is by employing blocks 11 between thelower faces of LOUIS N; MoDONALD.

the lugs 6 and upper end of the mold. The thickness of the blocks 11will vary, as-required, to change the distance the form member extendsinto the mold and in this way produce an ingot of the desired length andweight.

The refractory material may consist of any standard refractory material,however, good results have been obtained by using waste refractories,such as old fire-brick and other refractory furnace parts which havebeen crushed to the necessary granular form.

By practicing this method the interior of the upper end of the ingot ismaintained in a molten condition a suflicient length of time to preventthe formation of holes (piping) e in the main body of the ingot, whichis t function of the prior art hot tops. The prior art hot tops ingenerabuse, however,

are in the form of prepared refractory forms which are quite expensiveand in the ma- I jority of cases are usable with only one cast.

While I have shown and described one specific form of apparatus and amethod consisting of a certain sequence of steps as comprising myinvention, I. do not wish to be limited thereto since variousmodifications may be .made without departin from the scope of myinvention, as define in the appended claim.

I claim:

The method of casting ingots which includes mserting an upwardlytapering open ended metal form member centrally in the upper end of theingot mold and spaced from the sides of the mold, pouring the moltenmetal'through said form and into the mold, stopping the supply of-moltenmetal when the mold is filled up to a oint slightly above the lower endof said orm to permit the metal to solidify between said form and themold thencontinuing the pouring of the molten metal until said form isfilled, permitting the metal to chill until a skin is formed around theinterior of said form, then withdrawing said form and filling the spacebe- 0 In testimony whereof, I have hereunto set 7

